修复cp目标不存在问题：添加mkdir -p backend/dist确保目录存在

deploy.sh

@@ -20,8 +20,9 @@ npm install --include=dev
 npm run build
 cd ..
 
-# 4. 部署前端到backend/dist
+# 4. 部署前端资源...
 echo "4. 部署前端资源..."
+mkdir -p backend/dist
 rm -rf backend/dist/*
 cp -rf frontend/dist/* backend/dist/